diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services21.yml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services21.yml
index da717a8bb2..a2617c1688 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services21.yml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services21.yml
@@ -6,7 +6,7 @@ services:
         calls:
           - method: setLogger
             arguments:
-              - @logger
+              - '@logger'
           - method: setClass
             arguments:
               - User